There is no single national plant count. In the United States, the number of cannabis plants you may grow is set by the state you live in, then narrowed by county and city rules, and sometimes by a lease or HOA term. Among states that let adults grow at home, the working range runs from 2 to 12 plants per household, with 6 plants per adult and 12 per household as the most common pattern. If your plants are hemp grown for CBD, a second rulebook applies: your state hemp program plus the federal 0.3% THC threshold. Before you buy seeds, clones, or a grow tent, confirm three things: which rulebook covers your plants, whether your limit is per adult or per household, and whether plants must be tagged, registered, or kept in an enclosed locked space.
First, sort out which rulebook applies
Federal law still treats cannabis above 0.3% THC as a controlled substance, so plant counts for what most people call marijuana exist only in state statutes. Hemp, defined as cannabis at or below 0.3% THC on a dry weight basis, sits outside that framework as an agricultural commodity, but cultivation is licensed and tracked by state departments of agriculture.
The practical result: a home grow of high-CBD hemp plants is not automatically legal just because CBD products are sold in your state. Many hemp licenses are written for farms, with acreage reporting, pre-harvest testing, and a sampling window before harvest. Some states fold small hemp grows into the same plant counts as marijuana. Others do not allow unlicensed hemp cultivation at all. Check your state agriculture department page for hemp and your state cannabis regulator page for marijuana, and read both before you assume a number.
What to verify in the statute
- Age and residency: 21 and older is the adult-use norm; medical programs often start at 18 with a registry card.
- Per adult or per household: a 6-per-adult rule with a 12-plant household cap is common, and roommates can hit the cap fast.
- Mature vs immature: many states count flowering plants separately from seedlings and clones, so the headline number rarely means total plants in the room.
- Grow location: indoor, outdoor, or greenhouse only, plus setbacks from schools, parks, and property lines.
- Security: enclosed and locked space, locked gates, or an inaccessible area for anyone under 21.
- Registration and tagging: some states require plant tags, a cultivation registration, or reporting to a seed-to-sale system.
- Local overlay: city and county ordinances can reduce counts or ban home grow outright even where state law allows it.
- Possession math: dried flower limits in ounces usually apply on top of plant counts.
Typical parameter bands
These bands describe what most permissive states do, not a rule you can rely on. Treat them as a checklist of questions for your own state text.
Legal Cannabis Plant Limit Guide for CBD Stores in the US
- 2 to 3 plants: common for medical-only programs and for first-year registrations.
- 6 plants: the most frequent adult-use number, often tied to one adult and one residence.
- 12 plants: a typical household ceiling, and the usual cap with two or more adults.
- Canopy limits: some states regulate square footage of flowering canopy instead of plant counts, which rewards long vegetative cycles and penalizes large plants.
- Possession bands: 1 to 3 ounces of usable flower at home appears in many adult-use statutes.
Pitfalls that cause real trouble
- Counting seedlings as free. In states that define a plant by a visible root or a cotyledon pair, a tray of 20 starts can exceed your cap on day three.
- Assuming a medical card doubles your count. Some states raise the limit for patients; others keep the same household cap.
- Overplanting a shared house. Two adults at 6 each is fine in some places and a violation in others once the household cap applies.
- Ignoring the lease. A legal grow can still break a rental agreement or void insurance.
- Buying hemp seed marketed for CBD without a license path. Germinating licensed hemp seed without the state permit is a separate violation from marijuana rules.
- Assuming neighboring state rules travel with you. Plant counts do not cross state lines.
FAQ
Do clones and seedlings count toward my plant limit?
Depends on the definition in your state code. Many statutes count only plants with a visible root system or those past a set height, which is why growers start seeds in stages. Read the definition section, not the headline.
Can I grow more plants with a medical card?
Sometimes. Several states set a separate patient count or allow a caregiver to grow for multiple patients, but household caps often still apply. Verify the patient cultivation section separately from the adult-use section.
Can I grow CBD hemp at home without a license?
In most states, no. Hemp cultivation is licensed, tested, and reported, and THC content above the limit triggers a disposal or remediation requirement. A few states allow small home hemp grows, usually with a registration.
Does the federal farm bill let me grow hemp anywhere?
No. It sets the 0.3% THC definition and the federal framework; the license to cultivate comes from your state or tribal program, and local zoning still applies.
This is general information, not legal advice. Your state statute, your county code, and your lease are the three documents that decide your number.